1. Field of the Invention
The present invention relates to automotive suspension technology, and more specifically to shock absorber and strut assemblies and methods for using such assemblies in aftermarket modification.
2. Description of the Related Art
Shock absorbers have been used as a part of suspension systems for automobiles for many years as a means to lessen vibration of driving on rough road surfaces and to increase ride quality. Most strut assemblies commonly used on automotive vehicles include a shock absorber (dampener) with a coil spring. These strut assemblies are attached to the underside of a body of a vehicle and connect to the suspension. The upper mounting unit of such a strut assembly has a spring mounting unit and shock absorber shaft connection point which secures to the underside of the vehicle. The upper end of the spring sits in the upper mounting unit and extends downward surrounding the shock absorber. The spring mounts to a lower spring seat which is fixed to the exterior of the shock absorber. The shock absorber continues downward and connects to a steering knuckle or other component of the vehicle suspension. The combination of the spring and shock absorber lessens the vibration created while driving, and further plays a significant role in ride height. The coil springs are a given length when compressed with the load of the vehicle. The spring raises the riding height of the vehicle based on the location of the lower spring seat on the shock absorber. Depending on the vehicle, such a distance has been calculated, and the lower spring seat is fixedly attached to the shock absorber in a location to effectuate the desired lift in the vehicle.
Aftermarket modification of vehicles, specifically of suspension components, is a popular and ever-growing market. Markets have arisen for both the raising and lowering of vehicle ride height for both aesthetic purposes and for performance. Many cars and trucks are lowered and have modified suspension systems for improved handling in street applications; and many vehicles, including trucks, sport utility vehicles, and jeeps have raised ride heights and stronger suspension components for off-road applications. Many times the shocks and springs of such vehicles are replaced to change the handling characteristics of the vehicle. Softer or firmer coil springs may replace factory units in order to effectuate the ride preference of the driver. In addition, many different types of shock absorbers can be used offering the driver different options. When aftermarket components are used, they do not necessarily meet the dimensions of the factory units, and adjustment of the suspension may be necessary to obtain the desired ride height.
Aftermarket modifications, especially those which raise or lower the chassis of a vehicle, create unique problems not usually encountered with an unmodified vehicle. For instance, many modifications can be combined, thereby different dimensions and tolerances within the suspension system can be created which are not normally encountered. Further, some modifications may affect ride height by interchanging different components of the suspension of a vehicle. When this occurs, it may be desired to modify the ride height, but there is no simple method to effectuate such a solution. To compound the issue, labor on suspension systems can be difficult and time consuming. Accordingly, many consumers may be discouraged to modify the suspension of a vehicle due to the effort or the expense in labor costs to hire someone to install and properly configure an aftermarket suspension.
An example of a strut assembly that may be adjusted to change the vehicle ride height is disclosed in U.S. Pat. No. 6,902,045. However, the adjustment assembly disclosed involves the use of a ring gear that is adjusted by way of an outwardly protruding knob. Such a system includes inherent problems with regard to locking the ring gear in place, unintentional adjustment of the ring gear by accidental contact with the outwardly protruding knob, and further the difficulty to make exact adjustments in height. Additionally, wear on the ring gear may lead to failure thereby endangering the passengers of the vehicle.
Another strut assembly that allows for the adjustment in ride height is disclosed in U.S. Pat. No. 7,237,780. The device described in this patent uses a system involving two springs to adjust the ride height. This design includes a greater number of components thereby increasing costs and allowing for more potential points of failure.
It is therefore desirable to provide a shock absorber and strut system that is capable of being easily adjusted to raise or lower the ride height of the vehicle without the need to adjust or replace other components of the suspension.